Process of electric welding.



I A. L. JOHNSON- PROCESS OF ELECTRIC WELDING.

APPLICATION FILED APB..-17, 19 12.

Patented Sept. 24, 1912.

ALBERT L. JOHNSON, "or rrnmnnne, NEW YORK.

PROCESS 015 ELECTRIC WELDING.

. Specification of Letters Patent.

Patented Sept. 24, 1912.

Applica ion filed April 17, 1912. Serial No. 691,471.

To 'aZZ whom it may concern: I

Be it known that I, ALBERT L. J oHNsoN, a. citizen of the United States,and a resident of the town or Hamburg, county of Erie, and

. and economically.

The invention consists principally "in projecting a metal insert throughone of the members to be welded and against the other member and weldingsaid insert to said first member sidewise and to said second memberendwise.

It also consists in arranging the two members to be welded in anelectric circuit wherein they are connected by 'a metal insert whose endis in contact with one of said members and whose side is in contact withtheother, and then welding the parts together in this relation. I

It also consists in projecting a metal insert through a hole in one ofthe two members to be welded so that the sideof the insert is in contactwith one member and its end is in contact with the other member, saidmembers being otherwise out of contact and then welding the partstogether in this relation, meanwhile effecting pressure endwise of saidinsert. I

It also consists in projecting through a hole in one of the members tobe welded a metal insert which has a comparatively small area of contactwith the wall of said hole, bringing the second member into contact withthe projecting end of said insert, connecting said members to theopposite electrodes of a welding current, meanwhile ettecting endwisepressure on said insert.

It also consists in the operations hereinafter described.

In the accompanying drawing, which forms part or this specification, andwherein like symbols refer to like parts wherever they-occur, Figure 1is a diagrammatic view illustratingthe relation, at the beginning of theoperation, of the electrodes to the two metal la'tes to be weldedtogether; Fig. 2 is a simi ar view at the close of the operation;

Fig. 3 is a view similar to Fig. 1 showing a different design of rivetor metal insert; Fig. 4 shows the condition atthe end of the operationcorresponding to Fig. 3; and Fig. 5 illustrates various designs ofrivetsor inserts and their relation to the holes provided for them inone of the plates or members to be joined.

In carrying out the present process, a suit-- able electric weldingmachine is used; which it is unnecessary to describe in detail. Thiswelding machine is preferably equipped with two sets of electrodes, oneset 1, 2 of which may, for the purpose of distinguishing them from theother set, be designated as preliminary electrodesl The other set ofelectrodes 3, 4 may 'be designated as the pressure electrodes. Thepressure electrodes are in the form of pressure jaws arranged oppositeeach other, while the preliminary electrodes are preferably annular ortubular and are arranged concentric with the pressure electrodes. Thepreliminary electrodes and the pressure electrodes are located inseparate circuits 5, 6 or branches of the same circuit and the circuitcontrollers 7 are so arranged that the current first passes throu h thepreliminary electrodes and subsequent y through the pressure electrodes.

One of the metal plates or members 8, 9 to be welded together has one ormore holes 10 punched therein at a desired place or places; while theother metal plate or memher 9 is leftimperforate. The two plates arethen placed in proper relative position in the welding machine, butspaced slightly apart and with a fluted rivet or insert 11 in .the holeof the perforated plate. With the plates. in this relation, the electriccurrent is applied first through the preliminary electrodes andimmediately thereafter through the pressure electrodes, pressure beingmeanwhile applied to said pressure electrodes. ()n account of thecontact surface of the preliminary electrodes being of considerable areaand concentrically arranged, the electrical resistance to the currentthrough said electrodes is concentrated on the metal inserts and theportions of the plates nearest thereto, that is, on the wall or marginof the hole of one plate and on the small area of the other plateopposite the end of'said insert. The effect of this current on theinsert is to soften.- the end and side ribs or angles thereof to thecondition for welding, and the. adjamam .1

cent portions of the plates are likewise softened. The application ofthe current through the pressure electrodes with the lid . with eachother.

simultaneous application of the endwise pressure on the rivet or inserthasthe efi'ect of shortening the length of the rivet or insert andcausing the lateral expansion of the rivet or insert so as to fill thehole and weld its side to the wall of the rivet hole. Atthe same time,the projecting end-of the rivet in contact with the impert'orate platehas effected a concentration of the welding current on a small area ofsaid imperforate plate, and the end of the rivet is firmly and securelywelded to said imperliorate plate. The pressure endwise of the rivet hasthe edect of moving the plates closer togetheror into actual contact asmay be required and' subject to proper proportioning ot the parts andthe duration of the operation is prolonged or shortened.

Obviously, the form'oi rivet may be varied to suit the requirements ofthe designer.

By enlarging the portion of the rivet between the two plates, it may bemade to determine the proper spacing of the plates in the finishedarticle. For instance, with the design of rivet or insert illustrated inFig. l, the voids or spaces between the insert and the wall of the holeare suflicient to allow the inner projecting ortion of the rivet to beforced back into t e hole; in consequence of which the plates.ultimately contact flatwise 0n the other hand, rivets of the typeillustrated in Fig. 2, that is, a headed rivet, the projecting metal isin excess of the voids, and, in the finished article, the plates arespaced apart.

It is desirable that, whatever the form of the rivet may be, its area ofcontact with the wall of. the hole should be comparatively small, inorder that there should be an initial concentration of the current. Fig.5 illustrates a number of typical forms of rivets together with theirrelation to the hole with which they are intended to cooperate. lin likemanner, the end of the rivet should be convex or otherwise shaped so asto have a small area out contact with the plate So, too, in the case ofvery thick members, it may be desirable to form the hole only partiallythrough the same. I

Among the principal advanta of the present process, is the fact that inthe finished article the original perforated plate regains the tensileand compressive; strength ihat it had before it was perforated. Anotheradvantage is that by positioning the rivet in the rivet hole, the properrelation of the plates to each other with particular ref-' erence to thelocation oi the weld, can be-dei'ermined with great accuracy andfacility.

Another important advantage is that the siderable extent independentlyof the condit ons afi'ecting the operation of welding the scribed admitsof. considerable variation without departing from my invention.

What I claim is:

.1. The process of joining metal members which consists in forming ahole in one of said members and placing a metal insert herein with itsend projecting therefrom, placing an imperforate portion of the secondmember against the end of said insert, and electrically welding saidinsert to said members.

2. The process of joining metal members which consists in forming a holein one of said members and. placing a metal insert therein with its endprojecting therefrom, placing a second member against the end of saidinsert, and electrically welding said insert to said members underendwise pressure, the side wall of said insert having ribs to contactwith the wall of the hole, and the voids between the insert and the wallof the hole being of suficient volume. to permit the projecting portionof the rivet to be forced into the hole during the. welding oporation.

'3. The process of joining metal members which consists inarranging ametal insert to project through a hole in one member and bear endwiseagainst an imperitorate portion of the other member and electricallywelding the parts to ether by passing an electric current throng theperforated member, said insert and said second member serially. 4. Theprocess of joining metal members which consists in projecting a metalinsert through one of said members and into contact endwise with animperforate portion of the othm" member, passlng an electric currentfrom said first mentioned member through said insert'and thence throughsaid second mentioned member.

5. The process of joining metal members which consists in projecting ametal insert through one of said members and into contact endwise withan impert'orate portion oi the other member, passing an electric currentfrom said first mentioned member throu h said insert and said secondmentione member serially, said insert being meanwhile submitted to"endwise pressure.

6. The process of joining metal members which consists in projecting ametal insert through one of said members and into contact with the othermember, and passing an electric current from said first mentioned memberthrough said insert and said second mentioned member serially, saidinsert bewall of the hole in the first mentioned meming initially incontact with said first men- ;tioned member along only a comparativelysmall area of the side surface of said insert.

7. The process of joining metal members which consists in projecting ametal insert through one of said members and into contact with the othermember, and passing an electric current from said first mentioned memberthrough said insert and said second mentioned member serially, saidinsert being of polygonal section with its angular portionssubstantially in contact with the her. 7

s 8. The process of securing metal members together which consists inarranging a metal insert in a hole provided therefor in one of"other'member serially, and then passing an electric current endwisethrough the rivet and the imperfora'te member, meanwhile maintainingpressure endwise of the insert.

9. The process of securing metal members together which consists inarranging a metal insert in a hole provided therefor in one of saidmembers and projecting therethrough into contact with the other member,the members being meanwhile spaced apart, passing an electriccurrentfrom the perforated member through the insert and the othermember serially, and then passing an electric current endwise throughthe rivetand the imperforate member, meanwhile maintaining pressureendwise of the insert,

said insert initially having angular projections in contact with thewall of the hole, whereby voids are formed between said insert and thewall of the hole into which the metal may be pressed duringthe weldingoperation. Signed at ,St. Louis, Missouri, this 13th day of April, 1912.I

' ALBERT L. JOHNSON. Witnesses A EDGAR T. FARMER, M. A. SHELTON.

